Non-alcohol substance use disorder after bariatric surgery in the prospective, controlled Swedish Obese Subjects study.

OBJECTIVE: The goal of this study was to investigate whether bariatric surgery is associated with substance use disorder (SUD) with substances other than alcohol. METHODS: The prospective, controlled Swedish Obese Subjects study enrolled 2010 patients with obesity who underwent bariatric surgery (gastric bypass n = 265; vertical banded gastroplasty n = 1369; gastric banding n = 376) and 2037 matched control individuals receiving usual obesity care. Participants with SUD other than alcohol use disorder were identified using International Statistical Classification of Diseases (ICD) codes from the Swedish National Patient Register (covering treatment in hospital but not primary care). Those with a history of non-alcohol SUD were excluded. Median follow-up was 23.8 years. RESULTS: During follow-up, non-alcohol SUD incidence rates per 1000 person-years with 95% CI were 1.6 (0.8-3.1), 0.8 (0.5-1.2), 1.1 (0.5-2.2), and 0.6 (0.4-0.8) for gastric bypass, vertical banded gastroplasty, gastric banding, and control individuals, respectively. Only gastric bypass was associated with increased incidence of non-alcohol SUD (adjusted hazard ratio 2.54 [95% CI: 1.14-5.65], p = 0.022) compared with control participants. CONCLUSIONS: Gastric bypass surgery was associated with increased risk of non-alcohol SUD, and this should be considered in long-term postoperative care.